UDA50/RA81 problem -- HELP !

[rbbb at RICE.ARPA]

From:  David Chase <rbbb at RICE.ARPA>

Before running off and badgering your DEC field service people, why not look
for yourself?  Open the front of your machine, and look in the Unibus.  The
UDA50 occupies two hex slots, and has all sorts of gory lights and cables.
If you find two boards numbered M7161 and M7162, then you have an OLD UDA50.
Those are known to sometimes drop offline without any pattern or warning (we
had one that would run for weeks without this problem).  If the two boards
are numbered M7485 and M7486, then you have a NEW UDA50, and it should NOT
mysteriously drop offline.

Should you have an old UDA50, then you should get it upgraded.  The upgrade
replaces almost every board involved, and requires that you REFORMAT your
disk.  The OLD UDA50/RA81 diagnostics are NOT compatible with the NEW boards.

The NEW hardware should still work with existing drivers. (It does for us).

A good tool to use in this operation (backup, reformat, restore) is DEC
Standalone Backup, since it moves the bits much faster than existing unix
utilities.  We used it, and it worked great.  You MUST use a version from
VMS 3.4 or higher (there is an ominous-looking bug fix in the release notes
for 3.4, though we didn't and had no problems).  If you have any questions
on this, direct them to rbbb at rice.arpa; I have little knowledge of unix
device drivers, but lots on hardware, diagnostics, and VMS BACKUP (my
friend).

If DEC field service does not believe this, refer them to the
"UDA USER GUIDE", number EK-UDA50-UG-002.
That (plus sad experience) is where I got my information.

drc